This invention relates to a process for regenerating a spent extraction solvent containing anions and cations used in e.g. nuclear power plants by separating and removing these ions from the extraction solvent and an apparatus used therefor. This invention is particularly suitable for separating and removing ions contained in an organic solvent for reprocessing in large amounts.
Heretofore, an extraction solvent was regenerated by cleaning the extraction solvent with an alkaline cleaning agent such as sodium carbonate, triethanolamine, etc. by using a liquid-liquid extraction apparatus such as a mixer-settler, etc. (e.g. U.S. Pat. No. 4,059,671). But such a cleaning agent has problems in that it easily precipitates metal ions contained in the deteriorated solvent, the resulting precipitate is collected at an interface of the solvent and the cleaning agent thus interfering with the removal action of captured impurities and making the separation of the solvent and the cleaning agent worse.